1. Field
The present disclosure is directed to a method and apparatus for reporting channel state information.
2. Introduction
Presently, wireless communication devices, such as user equipment communicate with other communication devices using wireless signals. In current Third Generation Partnership Project Long Term Evolution (3GPP LTE) systems, time-frequency resources are divided into 1 ms subframes where each 1 ms subframe includes two 0.5 ms slots and each slot with normal Cyclic Prefix (CP) duration comprises 7 Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols in the time domain in Uplink (UL) and 7 Orthogonal Frequency Division Multiplexed (OFDM) symbols in the time domain in Downlink (DL). In the frequency domain, resources within a slot are divided into Physical Resource Blocks (PRBs), where each PRB spans 12 contiguous subcarriers.
In current LTE systems, resources are usually assigned using a 1 ms minimum Transmission Time Interval (TTI) when data is available, referred to as dynamic scheduling. Within each scheduled TTI, in UL, a wireless communication device, otherwise known as a User Equipment (UE), transmits data over a Physical Uplink Shared Channel (PUSCH) or a Physical Sidelink Shared Channel (PSSCH) in PRB-pairs indicated by an uplink/sidelink grant that schedules the data transmission to the UE. In DL, an enhanced NodeB (eNB), such as a base station, transmits data over a Physical Downlink Shared Channel (PDSCH) in PRB-pairs indicated by a DL grant/assignment. The UL/sidelink grant and/or DL assignment information is provided to the UE in a control channel, referred to as a Physical Downlink Control Channel (PDCCH) or enhanced PDCCH (EPDCCH). The (E)PDCCH channel carries the control information about the data being transmitted on the current subframe and the information about the resources which UE needs to use for the uplink/sidelink data.